Banana flower thrips are major pests in South East Queensland and northern New South Wales and minor in northern Queensland.

Thrips cause corky scab, which is primarily a problem in the drier banana-growing areas. In northern Queensland thrips are active throughout the year. Fruit harvested in winter or spring is usually the most affected, indicating that the period of greatest activity is after the wet season.

Fruit damage is caused by feeding and oviposition. Feeding damage results in slightly raised areas on the fruit that are grey-brown to grey-silver at first. They develop to form the corky raised areas of brown corky scab. Damage is confined in most cases to the outer curve of the fruit, particularly near the cushion end where the fruit finger joins the bunch stalk.

In severe infestations, damage can spread to other areas of the fruit. Bottom hands (closest to the male flower) are most at risk, but in severe cases, damage can extend to cover most of the bunch.

Oviposition on young fruit produces minute raised spots with a dark central tip on the fruit surface. This damage has little economic importance since it becomes almost unnoticeable as the fruit develops and matures.

No direct relationship between thrips numbers and subsequent damage is evident indicating that other factors, apart from pest numbers, are important in determining fruit damage.

A range of predatory bugs, ladybird beetles and lacewings assist in reducing thrips populations.

Removal of the male 'bell' where adult thrips move after all hands are exposed, may help in reducing thrips populations. This approach has not been evaluated. Evidence from observations and growers' reports suggest that overhead irrigation prevents corky scab in most situations.

Bunch injection with insecticide to control scab moth has been very successful in preventing corky scab development in northern Queensland. Treatments should concentrate on bunches which emerge during the period of maximum thrips activity (usually December to March), or at other times if previous experience has demonstrated a different activity period.

Throat applications to the emerging bunch have only proved partially successful. Cover sprays are not recommended because of disruption to beneficial species.


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The vast majority of the bananas currently grown and consumed were not conventionally bred but are selections made over probably thousands of years from naturally occurring hybrids. Cultivated bananas are very nearly sterile and as a consequence are not propagated from seed but rather through vegetative propagation, primarily suckers as well as more recently micropropagated or tissue cultured bananas. These factors, very old selections, near sterility and vegetative propagation, mean that these bananas have not been genetically improved either for resistance or improved quality and are becoming increasing in affected by serious pests and diseases.

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